I can't speak for other games that used GS but the server list in Halo is probably my favorite way to find a game. No waiting for Matchmaking, dealing with region locks, ect. You just pick what you want to play and jump right in. You see your ping, the map, the gametype, ect before you even join as soon as the list loads.
I'm surprised people even tolerate waiting in lists to find games nowadays, at least for FPS games. I could see it being annoying on consoles when using controllers, but really PC has no excuse. Usually games that use some form of matchmaking won't even show the number of available servers!